Presently the plug server is widely used in different parts of the world as a replacement to the heavy computing machines that the cloud computing offers or the highly scalable machines in the data center. This also adds to a lot of onus on protecting the data stored within the plug server.
A previously known application of the plug server is to enable survey data collection in some of the disconnected parts in the world. A team of workers typically shares a plug server, whereas each worker is equipped with a mobile device to collect data by means of a pre-installed mobile application. The plug server establishes a wireless network via an attached WIFI access point, and it is through this wireless network that the workers use the mobile devices to submit collected data to the plug server. The plug server has a pre-installed server application to accept data submitted by the mobile devices, and to save the data to the disk storage of the plug server.
A plug server typically has a processor, expandable memory, and removable disk storage. An eMMC flash disk is a common example of such storage. The data from one plug server can be physically swapped into another and made readable to an end user. When a team of workers carry out a survey in some of the most disconnected parts in the world, it is an important feature to bring additional flash disks for data storage while the team is out in the field, and swap the plug server for replacement flash disks when one disk runs out of space.
The server is typically protected by authentication. Previously known solutions include the use of a username/password login mechanism to secure access to any stored data. Another previously known solution is to use a physical USB device instead of a password for authentication in order to gain access to the server. In such a case, the physical USB device has been pre-registered with the plug server. The plug server can be powered on only in the presence of the registered USB device; otherwise the plug server is disabled by default without the same USB device.
Using of multiple physical flash disks creates a new problem that concerns the security and safety of the collected survey data, which are stored at rest on flash disks when not in use. The physical flash disks are at risks of being misplaced, mishandled, and vulnerable to theft. Previously known solutions attempt to provide protection by means of encrypting the data storage. While this technique protects survey data stored on a physical disk, it does not stop any unauthorized person from gaining access to the survey data if that person obtains the registered USB device, either legally or illegally, or perhaps by accident. This puts the survey data at rest on a disk at risk of being exposed to unauthorized tampering, especially after survey data collection is complete, resulting in a risk of invalidating the whole complete survey program due to questionable integrity of collected data.
Another previously known solution is to use an online-networked key server via the Internet, in an attempt to mitigate the risk associated with using physical USB devices as keys to the plug server. However, the key server in the solution requires the plug server to connect to the key server over the Internet, where the key server is typically hosted at some headquarters or some data centers in the home country. When a team of workers is conducting a survey out in the field of some disconnected foreign countries, Internet access is not readily available. Furthermore, Internet connection among foreign countries typically is subject to firewalls and potential government filtering, resulting in unstable and unreliable Internet connection. An interruption to Internet connection while a survey team is out in the field may potentially result in cancellation of a trip, or worse cancellation of a whole survey program.
Thus, there remains a considerable need for devices and methods that can protect integrity of survey data at rest on a removable storage disk, even in the case of obtaining a registered USB key device by an unauthorized person, from gaining access to the data stored on the removable storage disk.